exception is that the response calculations are
carried out using time-history (also known as
With the Nonlinear
Dynamic Procedure, the design displacements are
not established using a target displacement, but
instead are determined directly through dynamic
analysis using ground-motion histories.
analyses are highly sensitive to the modeling
assumptions and to the representation of the ground
motion. They are not prescribed by this document,
and should only be employed by experienced analysts
with express authorization of the cognizant design
Alternative Rational Analyses.
Nothing in this document should be interpreted as
preventing the use of any alternative analysis
procedure that is rational and based on fundamental
principles of engineering mechanics and dynamics.
Such alternative analyses should not adopt the
acceptance criteria contained in this document
without careful review as to their applicability. All
procedures should be subject to review by an
approved by the cognizant design authority, with
substantial experience in seismic design.